#include using namespace std; /*{{{*/ //template #define rep(i,n) for(int i=0;i<(int)(n);i++) constexpr int INF = numeric_limits::max()/2; constexpr long long LINF = numeric_limits::max()/3; #define mp make_pair #define pb push_back #define eb emplace_back #define fi first #define se second #define all(v) (v).begin(),(v).end() #define sz(x) (int)(x).size() #define debug(x) cerr<<#x<<":"< ostream& operator<<(ostream& os,const vector& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; } template ostream& operator<<(ostream& os,const pair& p){ os << "(" << p.first << ","<< p.second <<")"; return os; } template ostream& operator<<(ostream& os,const set& st){ os<<"{"; for(T v:st) os< inline void chmax(T &x,U y){ if(y>x) x = y; } template inline void chmin(T &x,U y){ if(y pii; typedef vector vi; typedef vector vvi; ll gcd(ll a,ll b){ if(b==0) return a; else return gcd(b,a%b); } //constexpr double eps = 1e-14; constexpr double eps = 1e-10; constexpr ll mod = 1e9+7; const int dx[]={1,0,-1,0} ,dy[] = {0,1,0,-1}; /*}}}*/ int main(){ ll n; cin >> n; ll x = 0; for(ll i=1;i<=n;i++) x^=i; if(x == 0){ cout << "X" << endl; }else{ cout << "O" << endl; } }